JP2002054588A - Fluid compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid compressor equipped with an enhanced reliability, compressing performance and easiness in the assembling operation by introducing such a structure that the bottom space of a spiral groove has sufficient communication with a compression chamber on the high pressure side, whereby it is possible to generate an optimum pressure, enhance the sealing performance by making smooth the blade coming into and going out of the spiral groove, and facilitate the operation to mount the blade in the spiral groove. SOLUTION: In a cylinder 5, a roller 14 eccentrical from the cylinder axis is stored, and is provided at its peripheral surface with the spiral groove 17 stretching in the axial direction, and the blade 18 is fitted in the spiral groove in such a way as capable of emerging and retracting, and a plurality of compression chambers 20 are formed between the blade, cylinder, and roller, wherein the groove shape at the section perpendicularly intersecting the longitudinal direction of the spiral groove is made in an inverted trapezoid in which the flanks on the low pressure side and high pressure side are inclining outward in the radial direction in such an arrangement that the opening angle θ ranges 0 deg.<θ<=20 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid compressor which is, for example, a helical blade type compressor constituting a refrigeration cycle of an air conditioner, and more particularly to a helical groove and a cross-sectional structure of a blade.

[0002]

2. Description of the Related Art For example, as a compressor constituting a refrigeration cycle of an air conditioner, a sealing failure which is often present in a reciprocating compressor or a rotary compressor is removed, and the sealing performance is improved with a relatively simple structure to improve efficiency. Helical blade compressors have been proposed that provide good compression and facilitate the manufacture and assembly of parts.

In this helical blade type compressor, as shown in FIG. 8, a roller b is eccentrically arranged in a fixed cylinder a, and a spiral groove c is formed on the outer peripheral surface of the roller so that the blade d can freely enter and exit. It is fitted in. With the revolving motion of the roller b, refrigerant gas is introduced into a compression chamber e formed between the blade d, the cylinder a, and the roller, and is compressed and discharged.

As shown in FIG. 9, the cross-sectional shapes of the spiral groove c and the blade d perpendicular to the longitudinal direction are mutually rectangular. The setting of such a cross-sectional shape is solely due to the requirement for workability of the spiral groove c.

[0005]

However, the spiral groove c
Since the blade and the blade d have a rectangular cross section, the communication between the groove bottom space of the spiral groove c and the compression chamber e on the high-pressure side is insufficient when the blade projects most from the spiral groove.

As a result, a pressure difference is generated between the groove bottom space of the spiral groove c and the high-pressure side compression chamber e, so that an optimum pressure rise cannot be obtained and the performance is reduced. At this position, an excessive differential pressure is applied to the blade d, resulting in a decrease in reliability, and a large deformation of the blade, making it impossible to smoothly enter and exit the spiral groove c, resulting in a decrease in sealing performance.

[0007] Further, in assembling the compression mechanism,
The blade d having a rectangular cross section has to be mounted in the spiral groove c having a rectangular cross section, and this operation is extremely troublesome, resulting in poor assemblability.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sufficient communication between a groove bottom space of a spiral groove and a compression chamber on a high pressure side to obtain an optimum pressure. In addition, the blades can smoothly enter and exit the spiral groove to improve the sealing performance, and the work of mounting the blade in the spiral groove is facilitated, improving reliability, compression performance, and assemblability. To provide a fluid compressor.

[0009]

According to a first aspect of the present invention, there is provided a fluid compressor according to the present invention, comprising: a hollow cylindrical cylinder; and a roller provided in the cylinder and having an eccentric center axis. A spiral groove provided on the outer peripheral surface of the roller along the axial direction, a blade fitted in the spiral groove so as to be able to protrude and retract, and a plurality of compressions formed between the blade, the cylinder and the roller. The spiral groove has a groove shape having a cross section orthogonal to the longitudinal direction of the spiral groove, and the low pressure side and the high pressure side are each formed in an inverted trapezoidal shape by inclining outward in the radial direction. θ is characterized by being expressed by the following equation (1).

0 ° <θ ≦ 20 ° (1) As a second aspect, in the fluid compressor according to the first aspect, the inclination angle φ of the side surface on the low pressure side at the opening angle θ of the spiral groove is as follows. (2).

0 ° <φ ≦ θ / 2 (2) As a third aspect, in the fluid compressor according to the first aspect, the cross-sectional shape orthogonal to the longitudinal direction of the blade is such that the side surfaces on the low-pressure side and the high-pressure side have Each is formed in an inverted trapezoidal shape by inclining outward in the radial direction, and the opening angle θ ′ thereof is expressed by the following equation (3) with respect to the opening angle θ of the spiral groove. .

Θ ′ ≦ θ (3) According to a fourth aspect, in the fluid compressor according to the second aspect, the cross section orthogonal to the longitudinal direction of the blade has a shape in which the side surfaces on the low-pressure side and the high-pressure side are radial directions, respectively. Is formed in an inverted trapezoidal shape by inclining outwardly, and the inclination angle φ ′ on the low pressure side is expressed by the following equation (4) with respect to the low pressure side inclination angle φ of the spiral groove. It is characterized by that.

Φ ′ ≦ φ (4) By adopting means for solving such a problem,
Sufficient communication between the groove bottom space of the spiral groove and the compression chamber on the high pressure side provides optimum pressure, smooth entry and exit of the blade into the spiral groove, and mounting of the blade in the spiral groove Work becomes easier.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a so-called helical blade type compressor which is a fluid compressor, which is of a horizontal type here. This helical blade type compressor is housed in a horizontally long hermetically sealed case 1 and has a rotating shaft 2 having an axial center extending in a horizontal direction, and a compression mechanism 3 on the right side in the figure connected via the rotating shaft. , The motor unit 4 on the left side.

A suction refrigerant pipe Pa is connected to a lower part of one side surface of the closed case 1, and a discharge refrigerant pipe Pb is connected to this upper part. The suction refrigerant pipe Pa from the discharge refrigerant pipe Pb
, The condenser, the expansion valve, and the evaporator are sequentially connected via a refrigerant pipe (not shown), and these constitute, for example, a refrigeration cycle of an air conditioner.

Next, the compression mechanism 3 will be described in detail. In the figure, reference numeral 5 denotes a cylinder, and flanges 5a integrally projecting from the outer peripheral surfaces of both sides of the cylinder 5 have a closed case 1
It is fitted to the inner peripheral wall, and attached and fixed from the outer peripheral side of the case by, for example, welding means.

The left and right ends of the cylinder 5 are open. The left end opening is closed by a main bearing 6, and the right end opening is closed by a sub-bearing 7.

The main bearing 6 has a boss 6a rotatably supporting a substantially intermediate portion of the rotary shaft 2, and a flange integrally formed at an end of the boss to protrude and close an opening of the cylinder 5. 6b.

The sub bearing 7 includes a boss 7a for rotatably supporting one end of the rotary shaft 2 and a flange 7b integrally provided around the boss to close the opening of the cylinder 5. Become.

The suction refrigerant pipe Pa is inserted through the end face of the sealed case 1 and inserted into the inside thereof.
Is connected to the connection hole 22 provided in the flange portion 7b. A suction guide recess 5b is provided at the end of the cylinder 5 facing the connection hole 22.

A lubricating oil guide plate 9 and a closing plate 10 are attached and fixed to the outer surface side of the sub bearing 7 via a fixture. An oil suction pipe 11 is connected to the lubricating oil guide plate 9 so as to suck lubricating oil stored at the bottom of the sealed case 1 and supply the lubricating oil to an oil guide groove 11 a provided on the peripheral surface of the rotating shaft 2. ing. The closing plate 10 contacts the end surface of the rotating shaft 2 and closes the opening of the guide plate.

In the rotary shaft 2, an eccentric crank portion 12 is integrally provided at a predetermined portion between the main bearing boss portion 6a and the sub bearing boss portion 7a. The eccentric crank portion 12 is eccentric by a predetermined distance from the axis of the rotating shaft 2.

The roller 14 is disposed eccentrically in the cylinder 5, and the amount of eccentricity of the rotary shaft 2 with respect to the center axis is the same as the amount of eccentricity of the eccentric crank portion 12. The axial length of the roller 14 is formed to be slightly smaller than the axial length of the cylinder 5, and a part of the outer peripheral surface of the roller is in rolling contact with a part of the inner peripheral surface of the cylinder 5 along the axial direction.

A shaft support hole 15 provided in the roller 14 is rotatably fitted into the eccentric crank 12 of the rotating shaft 2. Therefore, when the eccentric crank portion 12 rotates eccentrically with the rotation of the rotating shaft 2, the roller 14 makes an eccentric motion.

The sub bearing flange 7b and the roller 14
Between the lower end and the lower end, an Oldham mechanism 16 is provided, which controls the rotation of the roller 14 so as to perform a revolving motion.

A spiral groove 1 whose pitch gradually decreases from the upper end to the lower end is formed on the peripheral surface of the roller 14.
7 are provided. The spiral blade 1 is inserted into the spiral groove 17.
8 is inserted into the cylinder so that the blade can freely protrude and retract, and the outer diameter surface of the blade is in close contact with the inner peripheral surface of the cylinder 5. The sectional structure of the spiral groove 17 and the blade 18 will be described in detail in FIG.

The blade 18 is made of a synthetic resin material having a high degree of smoothness, for example, a fluororesin material. The blade 18 has an inner diameter larger than the diameter of the roller 14 and is forced into the spiral groove 17 with the diameter reduced. It is fitted.

As a result, the blade 18 is
At the same time, in a state where the blade 18 is incorporated in the cylinder 5, the blade 18 expands and deforms so that the outer surface of the blade 18 is always in elastic contact with the inner peripheral surface of the cylinder 5.

With the rotation of the rotating shaft 2, the cylinder 5
Since the rolling contact portion of the outer peripheral surface of the roller 14 with respect to the inner peripheral surface gradually moves along the circumferential direction of the cylinder, as the rolling contact portions approach, the blade 18 is immersed in the spiral groove 17 and The outer peripheral surface of the blade is completely flush with the peripheral surface of the roller 14 at the position facing the portion.

When the rolling contact portion passes, the blade 18 protrudes from the helical groove 17 according to the passing distance, and the protruding length becomes maximum at a portion 180 ° opposite to the rolling contact portion with respect to the axis. After that, since the vehicle approaches the rolling contact portion again, the above operation is repeated.

When the roller 14 and the cylinder 5 are sectioned in the radial direction, the roller and the cylinder are eccentric, and a part of the outer peripheral surface of the roller 14 and a part of the inner peripheral surface of the cylinder 5 are in rolling contact with each other. A crescent-shaped space is formed between the two.

When this space is viewed along the axial direction, the space between the roller 14 and the peripheral surface of the cylinder 5 is partitioned by the blade 18 into a plurality of continuous spaces. These spaces are called compression chambers 20, and the volume of each compression chamber 20 is gradually reduced from the right compression chamber to the left compression chamber based on the setting of the pitch of the spiral groove 17.

The right compression chamber 20 is opposed to the suction guide recess 5b provided in the cylinder 5 and the suction portion 20S which communicates with the connection hole 22 of the suction refrigerant pipe Pa. The left compression chamber 20 faces the discharge section 20D from a place communicating with the discharge guide hole 21 provided through the flange 6b of the main bearing 6.

A blade stopper 23 is arranged to face the end surface of the blade 18. With the revolving motion of the roller 14, the blade 18 protrudes and retracts from the spiral groove 17 and receives a force in a direction protruding from the end of the spiral groove.
The blade end face is abutted against the blade stopper 23 to restrict the protrusion from the spiral groove 17.

The motor section 4 faces a rotor 31 fitted to the rotating shaft 2 with a small gap on the peripheral surface of the rotor, and a stator fitted to the inner peripheral surface of the closed case 1. 32.

Next, the spiral groove 17 and the blade 18
Will be described. As shown in FIG. 2, as a groove shape in a cross section orthogonal to the longitudinal direction of the spiral groove 17, the side surfaces 17a and 17b on the low pressure side and the high pressure side are respectively inclined outward in the radial direction. It is formed in a shape.

[0038] Both side surfaces 17a of such a spiral groove 17,
The opening angle θ at 17b is designed to satisfy the following equation (1). 0 ° <θ ≦ 20 ° (1) The above equation (1) is obtained from the relationship characteristic of the opening angle θ (°) with respect to the compression performance (COP: coefficient of performance) shown in FIG.

This is a helical blade type compressor constructed as described above, and energizes the electric motor unit 4 to rotate the rotary shaft 2 together with the rotor 31. The torque of the rotating shaft 2 is transmitted to the roller 14 via the eccentric crank 12.

Since the Oldham mechanism 16 acts to regulate the rotation of the roller 14, the roller makes a revolving motion. As the roller 14 revolves, the rolling contact position of the outer peripheral surface of the roller with the cylinder 5 gradually moves in the circumferential direction, and the blade 1
The roller 8 moves in and out of the spiral groove 17 in the radial direction of the roller 14 while moving in and out.

By these series of operations, low-pressure refrigerant gas is supplied from the evaporator to the suction section 20 through the suction refrigerant pipe Pa.
It is sucked into the S-side compression chamber 20. Then, with the movement of the rollers 14, they are sequentially transferred to the compression chamber 20 on the side of the discharge unit 20D.

The volume of each compression chamber 20 is equal to the suction portion 20S.
From the side to the discharge unit 20D side,
The refrigerant gas is compressed while being sequentially transferred through each of the compression chambers 20, and is increased to a predetermined pressure in the compression chamber 20 closest to the discharge section 20D. The high-pressure gas in the compression chamber 20 is discharged from the discharge guide port to the condenser, and a well-known refrigeration cycle operation is performed.

As described above, the groove shape of the cross section orthogonal to the longitudinal direction of the spiral groove 17 is such that the side surfaces 17a and 17b on the low-pressure side and the high-pressure side are respectively inclined inwardly in the radial direction and inverted. Since the opening angle θ is set to be 0 ° <θ ≦ 20 °, which is the expression (1), the spiral groove 1
The communication between the groove bottom space volume of No. 7 and the compression chamber 20 on the high pressure side becomes sufficient, an optimum pressure rise is obtained, the reliability is prevented from deteriorating due to an excessive differential pressure applied to the blade 18, and the performance is improved. .

In FIG. 3, the opening angle θ and the compression performance (CO
(P: coefficient of performance), the spiral groove 17 protruding from the blade 18 increases as the opening angle θ increases.
The communication amount between the groove bottom space volume and the high-pressure side compression chamber 20 is increased. In particular, by setting 0 ° <θ ≦ 20 °, C
The improvement of OP is remarkable.

FIG. 4 shows the relationship between the spiral groove 17A and the blade 18A when the opening angle θ1 exceeds the limited range of the above equation (1). That is, when the opening angle θ1 is extremely large, the blade 18A
At the position most protruding from A, the blade is unlikely to deform corresponding to the spiral groove. For this reason, the blade 18A cannot be sufficiently pressed against the side surface 17a on the low-pressure side, and a gap is generated to deteriorate the sealing performance.

Therefore, as shown in FIG.
B is the opening angle θ limited by the above equation (1), and in particular, the inclination angle φ of the side surface 17a on the low pressure side is defined by the following equation (2): 0 ° <φ ≦ θ / 2 (2) 2) Limited to

As a result, the spiral groove 17B secures a predetermined opening angle θ, and at the position where the blade 18B protrudes most from the spiral groove, the blade is securely connected to the side surface 17a on the low pressure side of the spiral groove. The sealing performance can be ensured by being pressed against the substrate, and the phenomenon of the deterioration of the sealing performance as described above with reference to FIG. 4 can be mitigated.

FIG. 6 shows a state where the cross-sectional shape of the blade 18C is limited while the spiral groove 17 satisfying the expression (1) described above with reference to FIG. 2 is provided. That is, the cross-sectional shape orthogonal to the longitudinal direction of the blade 18C is formed in an inverted trapezoidal shape in which the side surfaces 18a and 18b on the low-pressure side and the high-pressure side are respectively inclined outward in the radial direction.

The opening angle θ ′ of the low pressure side and high pressure side surfaces 18 a and 18 b of the blade 18 C is the following expression (3) with respect to the opening angle θ of the spiral groove 17. θ ... (3)

Thus, at the position where the blade 18C most protrudes from the spiral groove 17, the blade is moved to the spiral groove 1
7, the upper end corner of the side surface 17a does not come into contact with the side surface 18a of the blade 18C, and stress concentration due to the upper end corner (edge) can be alleviated, thereby improving reliability. improves.

FIG. 7 shows a blade 18D whose sectional shape is further limited. As the helical groove 17B, a groove formed such that the inclination angle φ on the low-pressure side surface 17a described above with reference to FIG. 5 satisfies the expression (2) is applied.

The cross-sectional shape orthogonal to the longitudinal direction of the blade 18D is formed in an inverted trapezoidal shape in which the side surfaces 18a and 18b on the low pressure side and the high pressure side are respectively inclined outward in the radial direction. Then, the inclination angle φ ′ on the side surface 18a on the low pressure side.
Is limited to the following expression (4) with respect to the inclination angle φ on the low pressure side surface 17a of the spiral groove 17B: φ ′ ≦ φ (4)

Therefore, the blade 18D has the spiral groove 1
Even when the blade is pressed to the low-pressure side at the position most protruding from 7B, the upper end corner of the low-pressure side surface 17a of the spiral groove 17B does not contact the low-pressure side surface 18a of the blade, and the upper end corner ( Edge) can reduce stress concentration,
Reliability is improved.

In the above-mentioned helical blade type compressor, the roller has been described as a revolving type. However, the present invention is not limited to this. It is applied to the spiral groove of a helical blade type compressor with a structure.

[0055]

As described above, according to the present invention, the communication between the groove bottom space of the helical groove and the compression chamber on the high pressure side is sufficient, so that an optimum pressure can be obtained. Ingress and egress are smoothed, sealability is improved, and the work of installing the blade in the spiral groove is simplified,
This has the effect of improving compression performance and assemblability.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a helical blade type compressor that is a fluid compressor according to an embodiment of the present invention.

FIG. 2 is a sectional view of a spiral groove and a blade according to the embodiment.

FIG. 3 is a characteristic diagram showing a relationship between the opening angle of the spiral groove and the compression performance (COP) according to the embodiment.

FIG. 4 is a diagram for explaining performance degradation when a condition is not satisfied according to the embodiment;

FIG. 5 is a cross-sectional view of a spiral groove and a blade according to another embodiment.

FIG. 6 is a cross-sectional view of a spiral groove and a blade according to still another embodiment.

FIG. 7 is a sectional view of a spiral groove and a blade according to still another embodiment.

FIG. 8 is a sectional view of a conventional helical blade type compressor which is a fluid compressor.

FIG. 9 is a sectional view of the conventional spiral groove and blade.

[Explanation of symbols]

 5: cylinder, 6: main bearing, 7: sub bearing, 14: roller, 17: spiral groove, 18: blade, 20: compression chamber.

Claims (4)

[Claims] 1. A hollow cylindrical cylinder, and a roller housed inside the cylinder eccentrically with respect to a cylinder center axis.
A spiral groove provided on the outer peripheral surface of the roller along the axial direction, a blade fitted into the spiral groove so as to be able to protrude and retract, and a plurality of compression chambers formed between the blade, the cylinder and the roller. In the fluid compressor provided with, the groove shape of the cross section orthogonal to the longitudinal direction of the spiral groove, the low pressure side and the high pressure side are each formed in an inverted trapezoidal shape inclining outward in the radial direction, The opening angle θ is expressed by the following equation (1). 0 ° <θ ≦ 20 ° (1) 2. The fluid compressor according to claim 1, wherein the inclination angle φ at the side of the low pressure side at the opening angle θ of the spiral groove is expressed by the following equation (2). 0 ° <φ ≦ θ / 2 (2) 3. The cross section of the blade perpendicular to the longitudinal direction has a low trapezoidal side and a high pressure side, each of which is formed to have an inverted trapezoidal shape inclining outward in the radial direction.
The fluid compressor according to claim 1, wherein is expressed by the following equation (3) with respect to the opening angle θ of the spiral groove. θ '≤ θ ... (3) 4. The cross-section of the blade orthogonal to the longitudinal direction is such that the low-pressure side and the high-pressure side are each formed in an inverted trapezoidal shape by inclining radially outward, and the low-pressure side. 3. The fluid compressor according to claim 2, wherein the inclination angle φ ′ is expressed by the following expression (4) with respect to the inclination angle φ on the low pressure side surface of the spiral groove. φ '≤ φ ... (4)